Displays are used in various applications. For example, avionic and other vehicular systems use head down display (HDD) systems and head up display (HUD) systems including but not limited to wearable displays, such as, helmet mounted display (HMD) systems. In aircraft applications, HUD and HDD systems advantageously display information from aircraft systems and sensors in a graphical and alphanumeric format. The display information can include an enhanced vision image from a vision system (e.g., camera or other imaging sensor (such as a visible light imaging sensor, infrared imaging sensor, millimeter wave radar imager, or combinations thereof)). The display information can also or alternatively include a synthetic vision image from a synthetic vision system (e.g., computer generated graphics based upon a terrain and structure database).
HUDs generally include combiners disposed above the glare shield and can provide information conformally with the view of the environment through the windshield. Conventional HUDs cannot be used to conformally view information through the glare shield due to the opacity of the glare shield and equipment behind the glare shield. Modern cockpits are incorporating large area head down displays (LADs or LAHDDs) systems. The LADs can provide panoramic views and large areas to display information below the glare shield of the aircraft. However, such LADs do not provide HUD capabilities. Further, disposition of the LADs below the glare shield makes it difficult to provide an image continuous with the pilot's view of the environment.
Accordingly, there is a need for a display system that provides a continuous view of an outside environment despite the presence of a LAD. Further, there is a need to increase the vertical field of view of display systems used in aircraft and other vehicles. Further still, there is a need to integrate images provided on HDDs and HUDs. Yet further, there is a need for a HUD integrated with an LAD or other HDD in a cockpit or control center. Yet further still, there is a need for a compact HUD for use with an LAD. There is further a need for a display system that can provide an extended vertical view. Further still, there is a need for a virtual window image on a HDD that is compatible with a view through a combiner of a HUD. Yet further, there is a need for a vision system image or synthetic vision image that is integrated with the view from a combiner of a HUD.